The Health Behavior in School-aged Children (HBSC) study is a cross-national research survey conducted in collaboration with the World Health Organization (WHO) Regional Office for Europe. HBSC aims to gain new insight into, and increase our understanding of young peoples health and well-being, health behaviors and their social context. Initiated in 1982 in three countries, there are now over 40 participating countries and regions. The first cross-national survey was conducted in 1983/84, the second in 1985/86, and subsequently every four years using a common research protocol. The U.S. has been associated with the HBSC since 1993/94 and a fully participating member since 1997/98. The most recent survey was just completed for 2009/10. Besides contributing to the international survey, the U.S. simultaneously mounts a nationally representative school-based survey of approximately 10,000 students in grades 6 to 10 using identical data collection methods. Recent major studies from the 2005/06 survey have focused on the prevalence, patterns, determinants, and effects of violence and bullying behaviors, the epidemiology of substance use among young adolescents, the causes and consequences of physical inactivity, and the effect of public policy. A strength of the HBSC is the ability to make cross-country comparisons. With respect to bullying, involvement in bullying varied dramatically across countries, ranging from 10-67%, and was associated with poorer psychosocial adjustment. Trend analyses indicated that the U.S. was the only English-speaking country with a decrease in bullying involvement over the last 8 years. In all or nearly all countries, bullies, victims, and bully-victims reported greater health problems and poorer emotional and social adjustment. Victims and bully-victims consistently reported poorer relationships with classmates, while bullies and bully-victims reported greater alcohol use and weapon-carrying. With respect so substance use, the prevalence of adolescent drinking and drunkenness (except among Dutch girls) was generally lower in the United States, where strict drinking policies are in place, than in Canada and the Netherlands, where harm reduction policies are in place. However, the only difference in marijuana use rates was lower use by Dutch, a finding that is not consistent with the contention that prohibition-oriented policies deter use. Rates of student physical aggression were compared between Canada and the U.S. School, family, socioeconomic, and peer-related factors were considered as potential risk factors. A simple social environment risk score was developed using the US data and was subsequently tested in the Canadian sample. Risks for physical aggression were consistently higher among US vs. Canadian students, but the magnitude of these differences was modest. The relative odds of physical aggression increased with reported environmental risk. Electronic forms of bullying (e.g., email, cell-phone) were added to the 2005/06 survey. Prevalence rates of having bullied others or having been bullied at school for at least once in the last 2 months were 20.8% physically, 53.6% verbally, 51.4% socially or 13.6% electronically. Boys were more involved in physical or verbal bullying, while girls were more involved in relational bullying. Boys were more likely to be electronic bullies, while girls were more likely to be electronic victims. African-American adolescents were involved in more bullying (physical, verbal or electronic) but less victimization (verbal or relational). Higher parental support was associated with less involvement across all forms and classifications of bullying/victimization. Having more friends was associated with more bullying and less victimization for physical, verbal and relational forms, but was not associated with electronic bullying/victimization. With regard to risk factors for obesity, self-reported psychological andsocial health indices such as self-image, perceived health status, and quality of life were positively related to physical activity in representative countries from all international regions but, with a few exceptions, negatively related to screen-based sedentary behavior. Regional differences in correlates of physical activity and screen-based sedentary behavior suggest cultural differences in potential effects of physical activity and screen-based sedentary behavior and the need to tailor school and public health efforts to the different meanings of physical activity and screen-based sedentary behavior for positive and negative health consequences. NEXT examines a nationally representative cohort of 2,700 10th-grade students recruited during the 2009-2010 school year from 81 schools (both public and private) with an oversample of African-American students. In 10th grade, participants completed a survey focusing on substance use, obesity-related behaviors, driving, dating violence, and social networks. In addition, anthropometric data (height, weight, and waist circumference) and saliva (genetic material) were collected. Geocodes of home addresses are linked with other databases to provide neighborhood information and a school administrator survey provides information about school environment, programs, and policies. In 11th grade and 12th grades, participants complete the survey on-line or by phone and anthropometric measures are repeated. In the year after high school, participants complete the survey on-line or by phone. Using the anthropometric data gathered at the initial assessment, NEXT participants are categorized as overweight or normal weight based on CDC guidelines. A total of 280 overweight and 280 normal weight were randomly selected for participation in NEXT Plus. NEXT Plus participants complete three 24-hour dietary recalls, wear an accelerometer during waking hours to assess physical activity and sedentary behavior for 7 days, wear an actiwatch continuously for 7 days to assess sleep patterns, and complete an activity diary during the same 7-day period. Blood pressure is assessed in addition to repeating the anthropometric measures. Fasting blood samples are collected to assay fasting blood glucose, HbA1c, total cholesterol, triglycerides, LDL-C, HDL, C-reactive protein, uric acid, and cotinine. Participants in NEXT Plus complete a brief survey asking about the prescription or over-the-counter medicines he/she takes on a regular basis and details about the neighborhood where he/she lives. The participants primary caretaker is asked to complete a brief survey about the adolescents chronic illness and medicine use. During the 3rd year of the study, a subsample of participants will be recruited to have their cars instrumented to evaluate driving performance during a 12-month period.